RFC 2072 Router Renumbering Guide January 1997 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Motivations for Renumbering . . . . . . . . . . . . . . . . 3 4. Numbering and Renumbering. . . . . . . . . . . . . . . . . . 9 5. Moving toward a Renumbering-Friendly Enterprise. . . . . . . 13 6. Potential Pitfalls in Router Renumbering. . . . . . . . . 20 7. Tools and Methods for Renumbering . . . . . . . . . . . . 25 8. Router Identifiers . . . . . . . . . . . . . . . . . . . . . 29 9. Filtering and Access Control . . . . . . . . . . . . . . . . 35 10. Interior Routing . . . . . . . . . . . . . . . . . . . . . . 37 11. Exterior Routing . . . . . . . . . . . . . . . . . . . . . . 39 12. Network Management . . . . . . . . . . . . . . . . . . . . . 41 13. IP and Protocol Encapsulation . . . . . . . . . . . . . . . 43 14. Security Considerations. . . . . . . . . . . . . . . . . . . 44 15. Planning and Implementing the Renumbering . . . . . . . . . 44 16. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 46 17. References . . . . . . . . . . . . . . . . . . . . . . . . . 47 18. Author's Address . . . . . . . . . . . . . . . . . . . . . . 48 1. Introduction Organizations can decide to renumber part or all of their IP address space for a variety of reasons. Overall motivations for renumbering are discussed in [RFC 2071]. This document deals with the router- related aspects of a renumbering effort, once the decision to renumber has been made. A renumbering effort must be well-planned if it is to be successful. This document deals with planning and implementation guidelines for the interconnection devices of an enterprise. Of these devices, routers have the clearest association with the IP numbering plan. Planning begins with understanding the problem to be solved. Such understanding includes both the motivation for renumbering and the technical issues involved in renumbering. 1. Begin with a short and clear statement of the reason to renumber. Section 3 of this document discusses common reasons. 2. Understand the principles of numbering in the present and planned environments. Section 4 reviews numbering and suggests a method for describing the scope of renumbering. Berkowitz Informational